diff --git a/src/map_label.hpp b/src/map_label.hpp
index a0b5bf2c9d0..89beef0ade8 100644
--- a/src/map_label.hpp
+++ b/src/map_label.hpp
@@ -17,6 +17,7 @@
 
 #include "map_location.hpp"
 #include "font.hpp"
+#include "tstring.hpp"
 
 #include <map>
 #include <string>
diff --git a/src/menu_events.hpp b/src/menu_events.hpp
index a071059c3da..ea50c096f07 100644
--- a/src/menu_events.hpp
+++ b/src/menu_events.hpp
@@ -23,6 +23,7 @@
 #include "unit_map.hpp"
 
 class game_state;
+class gamemap;
 class tod_manager;
 
 namespace events {
diff --git a/src/multiplayer_wait.hpp b/src/multiplayer_wait.hpp
index 9ec8b374735..093442c7821 100644
--- a/src/multiplayer_wait.hpp
+++ b/src/multiplayer_wait.hpp
@@ -23,6 +23,7 @@
 #include "leader_list.hpp"
 #include "gamestatus.hpp"
 #include "multiplayer_ui.hpp"
+#include "src/show_dialog.hpp"
 
 namespace mp {
 
diff --git a/src/network_async.hpp b/src/network_async.hpp
index 1ebdefd49a2..514eebe2868 100644
--- a/src/network_async.hpp
+++ b/src/network_async.hpp
@@ -66,6 +66,8 @@ Feature Requests:
 
 #include "ana/api/ana.hpp"
 
+class config;
+
 /** Namespace of the asynchronous network API. */
 namespace network
 {
diff --git a/src/persist_var.hpp b/src/persist_var.hpp
index 3ee7c94d209..29194a7df3f 100644
--- a/src/persist_var.hpp
+++ b/src/persist_var.hpp
@@ -14,6 +14,9 @@
 
 #ifndef PERSIST_VAR_H_INCLUDED
 #define PERSIST_VAR_H_INCLUDED
+
+class vconfig;
+
 void verify_and_set_global_variable(const vconfig &pcfg);
 void verify_and_get_global_variable(const vconfig &pcfg);
 void verify_and_clear_global_variable(const vconfig &pcfg);
diff --git a/src/terrain_filter.hpp b/src/terrain_filter.hpp
index f5a8fa83009..046031e0345 100644
--- a/src/terrain_filter.hpp
+++ b/src/terrain_filter.hpp
@@ -17,6 +17,7 @@
 
 #include "map_location.hpp"
 #include "pathutils.hpp"
+#include "terrain_translation.hpp"
 #include "variable.hpp"
 
 class config;